Summary

The oxygen consumption of Ehrlich ascites tumor cells has been measured in relation to the content of various substances (glucose, pyruvate, hydrogencarbonate, phosphate, monoiodoacetate, malonate, and dinitrophenol) added to the suspension medium. The results, the findings on the glucose turnover, the formation of lactic acid and of hexosephosphates, as well as the results of other authors made it possible to elaborate a scheme of reaction, in which the reduction of TPN is the determinating factor in the inhibition of oxygen consumption by addition of glucose. The dependence of the Crabtree effect on the glucose concentration and phosphate content of the medium occurs as a result of the turnover rate of glucose via the hexosemonophosphate pathway.